Random DLC for Any Game

[Zexy]

I have a Steam Random Key and I want to add it. I'm trying to add it but Steam says "Fistly purchase game" but I don't know Which game. How can I learn it?

[ElvisDeadly]

You could ask the person who gave you the key?

[wuddih]

easy way:
install SteamDB extension[steamdb.info] for your normal web browser.

go: https://store.steampowered.com/account/registerkey
and enter the key it will tell you.

without extension, you will require a normal webbrowser anyway, same url, browser console, product name will be in the response to XHR post request to /account/ajaxregisterkey/ after you submit the key of course.

warning:
this is of course not for testing keys, that is the normal web version to register Steam keys to an account ... and as soon as you activate a key that would add something that your account(even blank hidden subids) does not have, the key will be used.